Flexible synthetic plastic sheeting

Abstract: The invention relates to synthetic plastic sheeting which is in the form of a flexible synthetic plastic film of material which has a biocide incorporated therein. The biocide can serve to inhibit the growth of different micro-organisms that cause bio-deterioration and, as such, the film can be used for packaging of or the covering, or protection of, products and objects that are exposed to bio-deterioration. The sheeting can also be provided in a sleeve form (12) permitting fitting on timber poles, for covering regions of poles to be disposed underground, in use, thereby protecting these regions against bio-deterioration.

Description: This invention relates to a synthetic plastic sleeve formed of a synthetic plastic sheeting. Synthetic plastic sheeting has a wide application within the packaging industry, as well as in various other industries and applications, where it is used for covering and/or protecting different articles, objects, and other subject matter. Many of the applications of synthetic plastic sheeting are associated with subject matter that is exposed to bio-deterioration as a result of the growth of different micro-organisms and where the subject matter has to be treated with or exposed to, for example, biocides, in order to inhibit the growth of micro-organisms. Many different biocides are known for the purpose, biocides being provided in the form of liquids, pastes, powders, solids, and other forms, in order to facilitate the treatment of subject matter and/or the exposure of subject matter thereto. When subject matter that is exposed to bio-deterioration is required to be packaged within, covered by, or protected by synthetic plastic sheeting, the treatment with or exposure to suitable biocides constitute separate and time consuming operations. As such, it is an object of this invention to at least alleviate this problem and to provide for required biocide treatment an/or biocide exposure to be facilitated. According to the invention there is provided a synthetic plastic sleeve formed of a synthetic plastic sheeting which comprises a liquid impervious, non-biodegradable flexible synthetic plastic film of material which has a dry-film biocide for inhibiting the growth of microorganisms that cause bio-deterioration incorporated therein the sleeve being dimensioned to fit onto a predetermined diameter timber pole for covering a desired area thereof and having shrinkage properties to permit secure location of the sleeve on the timber pole by being shrunk onto the pole through heating. The product of this invention is thus provided in the form of a liquid impervious, non bio-degradable elongated sleeve that can be fitted onto a timber pole to be supported in the ground for covering a desired area of the pole, i.e. the area of the pole that is exposed to sub-soil decay caused by a range of common and widespread fungi which inhabit the ground. Elongated sleeves provided for the purpose may have predetermined dimensions and shrinkage properties, permitting the sleeves to be fitted onto poles having predetermined diameters and to be securely located by being shrunk onto the poles by heating. The synthetic plastic film forming the sleeve and having the biocide incorporated therein may be extruded, having the biocide incorporated into the plastic material of which the film is formed, prior to the extrusion thereof. Furthermore, the synthetic plastic material of which the film is formed may be provided in granular form and the biocide may be incorporated therein in a powder or liquid form prior to extrusion of the synthetic plastic film. Still furthermore, the synthetic plastic material of which the film forming the sleeve is formed may be one of low density polyethylene, linear low density polyethylene, polyvinyl chloride, cross linked polyethylene, and the like. The biocide incorporated in the material of the synthetic plastic film forming the sleeve is a dry-film biocide. As such, the biocide may include urea derivatives, isothiazolinone and glycols. One known biocide of this type is the biocide known in the trade as MYCAVOID DFP. The sleeve of the invention can thus form a physical barrier in the form of a liquid impervious non-bio-degradable layer of material over a predetermined region of a timber pole where sub-soil decay of the pole can be prevented, or at least reduced, the biocide content of the sheeting enhancing the qualities of the material used for this purpose. Clearly, the specific synthetic plastic material used may be variable. The regions of poles to be protected may be determined by specific applications of the poles, as well as the soil characteristics of the soil in which poles are to be supported. Furthermore, the synthetic plastic material qualities required for the above application may be variable, as well as the specific biocide incorporated into this material. A particular example of flexible synthetic plastic sheeting, in accordance with the invention, is described hereinafter, as well as an example of one application of this flexible synthetic plastic sheeting which is illustrated by way of the accompanying drawing, which shows schematically in side view a sleeve formed of flexible synthetic plastic sheeting, in accordance with the invention, applied onto a timber pole. One particular example of flexible synthetic plastic sheeting, in accordance with the invention, is in the form of a low density polyethylene film incorporating therein a biocide of a type known in the trade as MYCAVOID DFP. This biocide is a dry film biocide and includes urea derivatives, isothiazolinone and glycols, which inhibit the growth of micro-organisms That cause bio-deterioration. Furthermore, this biocide is provided in a powder form and is dispersed into granules from which the film forming the plastic sheeting is formed, typically by an extrusion process. Particularly, the powder biocide and the granules may be mixed and provided in master batches, from which sheeting can be extruded. The method of producing this synthetic plastic film therefore provides for the dispersion of the biocide in its powder form into the granules from which the film is formed in order to form master batches, following which the sheeting can be formed by a conventional extrusion process, or any other conventional plastic sheet forming process. The biocide used clearly also can be incorporated into the material for forming a plastic film while in a liquid form. The film forming the sheeting is provided in a sleeve form that can be fitted onto a section of a timber pole that is ordinarily disposed underground in the operative configuration of the timber pole. The sleeve can thus form a physical barrier in the form of a liquid impervious, non-bio-degradable layer of material over the section of the pole, where it is anticipated that sub-soil decay is most likely to occur. The biocide content of the film forming the sleeve will thus enhance the effective inhibition of micro-organism growth that will otherwise cause bio-deterioration of the pole. In Figure 1, there is illustrated a timber pole that has a sleeve 12 formed of a flexible synthetic plastic film forming synthetic plastic sheeting, in accordance with the invention, fitted thereon, the sleeve 12 typically being of low density polyethylene, which has predictable shrinkage qualities so that the location of the sleeve on the pole takes place by fining the sleeve over the required region of the pole and then securely locating the sleeve by heat shrinking it onto the pole. It will be understood that the sleeve 12 fitted onto a pole 10 can cover any desired region of a pole and in the drawing shown, the sleeve 12 covers the typical region of a pole that is most exposed to bio-deterioration as a result of the growth of micro-organisms, when supported in a soil body 14. It will be understood also that synthetic plastic sheeting, in accordance with the invention, provided in different forms also can be applied onto timber poles to effectively form a sleeve as proposed and to thereby perform the function as suggested. Once again, the specific qualities of the sleeve will be determined by the soil characteristics of soil in which poles to be protected are to be supported. As such, different synthetic plastic materials can be used for different applications. as well as different biocide compounds.

Claims: A synthetic plastic sleeve formed of a synthetic plastic sheeting which comprises a liquid impervious, non-biodegradable flexible synthetic plastic film of material which has a dry-film biocide for inhibiting the growth of microorganisms that cause bio-deterioration incorporated therein, the sleeve being dimensioned to fit onto a predetermined diameter timber pole for covering a desired area thereof and having shrinkage properties to permit secure location of the sleeve on the timber pole by being shrunk onto the pole through heating. A synthetic plastic sleeve as claimed in Claim 1, characterized in that the synthetic plastic film having the dry-film biocide incorporated therein is an extruded film having the dry-film biocide incorporated into the plastic material of which the film is formed, prior to the extrusion thereof. A synthetic plastic sleeve as claimed in Claim 2, characterized in that the synthetic plastic material of which the film is formed is provided in granular form and the dry-film biocide is incorporated therein in a powder form prior to the extrusion of the synthetic plastic film. A synthetic plastic sleeve as claimed in Claim 2, characterized in that the synthetic plastic material of which the film is formed is provided in granular form and the dry-film biocide is incorporated therein in liquid form prior to the extrusion of the synthetic plastic film. A synthetic plastic sleeve as claimed in any one of Claims 1 to 4, characterized in that the synthetic plastic material of which the film forming the sleeve is formed is of one of low density polyethylene, linear low density polyethylene, polyvinyl chloride and cross-linked polyethylene. A synthetic plastic sleeve as claimed in any one of Claims 1 to 5, characterized in that the dry-film biocide incorporated in the material of the synthetic plastic film forming the sleeve includes urea derivatives, isothiazolinone and glycols.

Inventors: BAECKER ALBIN ALEXANDER WLADYS, HOSE RICHARD, BAECKER, ALBIN ALEXANDER WLADYSLAW, HOSE, RICHARD, Hose, Richard c/o Baecker, A. A. W.
Applicants: BIOTECHNOLOGY INTELLECTUAL PRO, BIOTECHNOLOGY INTELLECTUAL PROPERTY N.V.
Application year: 1994
Main classification: B29D7
IPC codes: B29D7, E04H12, B65D81, B29C61